I was thinking about this last night, trying to think of some of the earlier anime I had checked out but never bothered finishing.
One series that I never finished was called Gasaraki. I had bought some of the first 2 vhs that had come out, then bought one when they came out on dvd but never bothered to pick up the rest of the series. i think i'm gonna try and find it so I can see what happens. I remember it being cool with some mechs and a decent story, but it was just a slow moving anime.
Another one is Monster. A friend of mine recommended it to me and I started checkin out some episodes online to see if I would like it, and it seemed really good. Then I found the manga and figured I'd read that first and I just never bothered finishing either one. I think this week i'm gonna revisit that one as I've heard the whole series is excellent.